: not to be outdone, romney ratcheted up his campaigning in nevada. >> well, you know, he as, uhm, he has been reduced to trying to defend characters on sesame street and -- [ laughter ] >> word games of various kinds. >> reporter: and in a race this tight, both need all the face time they can get. it's one of the reasons that in just 14 days the candidates and their supporters will spend $100 million in tv ads especially since the polls are closer than ever. in ohio, the president's lead has shrunk to just 2 points. in florida, romney has the advantage by one and in virginia it's a dead heat. mark has conducted polls for three decades and says because it's so close, the candidates will likely decide their final campaign moves based on polling. >> absolutely. the key in the next few weeks is where can the candidate go where they can make the most difference and get some publicity for their visit? >> reporter: bob says that media will become increasingly important in the swing states because at this point, the tv markets are already saturated. there's no more ad space to buy. and it's probably